Control of the council has swung back and forth. In its first four years (1973-1977) there was no overall control, but in 1977 the Conservatives gained a majority. In 1981, this became a majority for Labour, and from 1985 there was again no one-party control. In 1997, Labour again took control, but lost it in 2001. Since then, no party has had a majority.

In 2008, the county council rejected a proposal to introduce a directly elected mayor, opting instead for a cabinet-style administration that resembled the status quo.[8] During the same year, an administration of Conservatives and Liberal Democrats collapsed, suffering not least from lacking a majority in the council. Thirty-nine Labour members and three Independents exactly equalled the total of thirty-two Conservatives and ten Liberals. A minority Labour administration then took over running the council until the June 2009 elections, when a net gain of one seat from the Independents led to the creation of a new Conservative and Labour coalition.[9]

The first elections to the authority were in 1973, and members have been elected since then every four years for a four-year term of office, with elections being held all together on the "first past the post" system.

Since boundary changes in 2001, 84 councillors have been elected from 84 single-member electoral divisions.[10]